Shell fuse



O. D. LUCAS.

SHELL FUSE.

APPLICATION FILED FEB. 16, 1922.

1,415,593 Patented May9,1922.

0 MW IOMHAL' iiww warren stares ears em.

OWEN DAVID LUCAS, OF BAYSWATER, LONDON, ENGLAND, ASSIGNOR TO V. M. I.

EXPERIMENTAL LIMITED, OF WESTMINSTER, LONDON ENGLAND. 4

SHELL rusn To all whom it may concern:

Be it known that I, OWEN DAVID LUCAS, a subject of the Kin of Great Britain, residing at 49 Linden ardens, Bayswater, in the county of London, England, have invented certain new and useful Improvements in Shell Fuses, of which the following is a specification.

his invention relates to sensitive shell fuses of the type provided with a striker piston acted upon by the pressure of air during the flight of the shell to move the striker into sensitive position.

According to this invention both the striker and the detonator pellet are provided with piston surfaces adapted to be acted on by air pressure due to the flight of the shell and'to move forwardly under such pressure into position for firing on impact. The fuse in this condition bein sensitive so that the striker operates on t e nose of the fuse meeting any obstruction which reduces the air pressure behind the forward piston. The striker and pellet are both held in the rearward position prior to discharge of the shell from the gun and on discharge are released to allow, during flight, the front member (usually the striker) to move forward.first, the rear member following up under the action of the air pressure.

In order that the said invention may be clearly understood and readily carried into effect, the same will now be described more fully with reference to the accompanying drawing, which shows in longitudinal section a sensitive fuse embodying this invention the fuse being fitted to a delay action or xed time fuse ensuring explosion of the shell at the end of a redetermined in-. terval in case the sensitive use has not acted.

A is'the fuse body. B is the striker screwed into the striker piston B. C is the detonator pellet with piston C. both pistons B and C being situated at the rear of their respective fuse members. pin for the striker, the pin havin a sli htly conical end 03 acting against a ba 1 d adapted to bear against the bevelled edge I) of the striker piston B, the set back pin being held up by a shearing pin (1 D is a set back pin adapted to hold the pellet C n safety position through the contrifugal pin d the pin D being held normally by the shearing pin (1 E is the fixed time fuse body carryingthe magazlne F and provlded.

Specification of Letters Patent.

coil ,ried in the D is a set back Patented May 9,1922.

Application filed February 16, 1922. Serial No. 536,858.

with the fixed striker G and detonator pellet G secured by a safety pin at g and when released by the safety pin held in a forward position by the spring 9, a fuse composition 7 of ordinary'type leading to the charge f in the magazine F.

' The striker B is of hollow or tubular formand is provided with the head I) of mushroom shape, following the contour of the nose of the fuse body when in normal position andperforated at b with a number of holes which reduce the area subjected to air pressure during flight. The striker is carplug a screwed in the end of the fuse body i The firing pin 6 projects from the rear end of the striker into the detonator chamber H, in front of which is the cylinder J within which the striker piston B lies, the pellet piston C lying in the rear cylinder H at the back of the chamber H. The cylinder J is shown of somewhat larger diameter than the cylinder H, which in its turn is substantially larger in diameter than the detonator chamber H. The set back pins D and B lie in the longitudinal passages'a and a of the body A and when the setback pin D moves rearwardly on discharge of the shell and opens up the forward portion of the passage a communication is afforded between the cylinder J and the rear end of the cylinder H, behind the pellet piston G, through the small passage a leading from the cylinder J into the passage a and the hole a leading from the passage a" into the rear end of the cylinder H. Both the cylinders H and J are open to the atmosthe initial action is to release the set back pins D and D, the inertia of which breaks through the shearing pins (Z and d, the pins D and D flying into the rear ends of the passages afa. flies back the ball 03 is released and the striker, piston B is free to move forward. The air pressure during flight acts on the When the pin D Y of the head owing to the heads b of the striker, but the area of the piston B is substantially eater than that oles I) provided in the latter. The air pressure transmitted through the hollow striker and the air holes 6 into the detonator chamber H and behind the piston B, acting in conjunction with the suction in front of the said piston through the suction holes j, moves the piston and striker forward into the position shown in dotted lines. A small leakage hole 6 is formed in the striker piston B, allowing air to leak from the back of the piston to the front, where there is reduced pressure. This leakage hole serves to regulate the speed at which the striker moves forward and assists in maintaining it in a highly sensitive'condition when in the forward position, the suction holes j drawing a stream of air continuously through the cylinder J and the leakage hole b. In this position the striker pin 6 is displaced to the forward end of the pellet chamber H.

The release of the de'tonator pellet is practically simultaneous with that of the striker, the set back pin D on itsJearward movement releasing the centrifugal pin d which immediately flies out so that its conical end, which in safety position lies over the bevelled forward edge of the pellet C, is withdrawn and the pellet C is therefore free to move forward. The set back of the pin 1). opens the passage a and communication is established between the rear end of the cylinder J and the back of the cylinder H as already described, so that air pressure in the cylinder I-I is allowed to act on the back of the pellet piston C and as the area of this piston is substantially greater than the area of the front of the pellet the pellet moves forward. The suction holes hleading from tlie forward end of the cylinder H into the rear groove a of the body A assist in the action by reducin the pressure in front of the piston C; s soon as the pellet has moved forward into osition ready for firing, the centrifugal alls '0,

which are thrown outwardly by the rotation of the shell, enter the annular groove h in the wall of the cylinder H, locking the pellet in its forward position.

Two set back pins D, D areshown in the construction illustrated, but a single pin could be .employed to hold both the ball d and the centrifugal pin (2 I now the shell with the fuse in its sensitive condition strikes any obstruction, for

example, the fabric of an airship, which while offering only a minute resistance to the passage of the shell blocks up the free entry of air through the hollow striker B into the cylinder J, the pressure at the back of the striker piston B is immediately reduced and the rearward air pressure on the striker and the striker head (with any added pressure due to the obstruction) instantly moves back the striker and causes the firing pin 6 to fire the detonator, igniting the charge f in the magazine F, through the flash hole f If for any reason the sensitive impact fuse does not detonate the shell is exploded by the fixed time or delay action fuse E on which the sensitive fuse is mounted, but the fixed time fuse forms no part of the present invention and is shown merely to complete the illustration of the fuse construction. On discharge of the shell from the gun the pellet G of the delay action fuse flies back against the striker G and the fuse composition f is ignited.

What I claim and desire to secure byLetters Patent of the United States is 1. In a shell fuse of'the kind set forth, a striker, a detonator pellet and means, under the control of air pressure due to the flight of the' shell, whereby both the striker and the pellet are caused to move forwardly from safety position into position for firing on impact.

2. In a shell fuse of the kind set forth, a striker, a detonator pellet, piston members'on the striker and the pellet and cylinders receiving the said piston members, which cylinders are open, behind the respective pistons, to air pressure due to the flight'of the shell, whereby both the striker and the pellet are caused to move, forwardly from an external head of mushroom form mounted on the outer end of the striker, which head is provided with a number of holes to reduce gheharea subjected to air pressure during 1g t. I

4. In a shell fuse of the kind set forth, a striker situated at the forward end of the fuse and provided with a mushroom head following the contour of the nose of the fuse, a detona'tor pellet situated behind the striker and means, under the control of air ressure due to the flight ofthe shell, by w ich the striker is first moved forwardly so that the head projects clear of the nose of the shell and the detonator ellet is caused to follow up the movement 0 the striker, whereby both striker and pellet are broughtinto sensitive position for firin' on impact. 5. In a fuse of t e kind set forth, a striker and a detonator pellet both provided with pistons and both adapted to take up a rearward and a forward position, a pair of cylinders in the fuse body receiving the said pistons and air pressure channels leading from the front 0 the fuse to the said cylinders behind their respective pistons, for the purpose specified.

6. Ina fuse as claimed in claim 5, means for holding the detonator. pellet in its formates ward position behind the striker after displacement of the pellet and striker into position for firihg on impact. v

7. In a fuse of the kind set forth,a pair of cylinders in the fuse body, a striker and a detonator pellet both provided with pistons adapted to be displaced under air pressure due to flight of the shell from the rear to the forward part of the said pair of cylinders; a set back pin or pins holding the striker and pellet in rearward inoperative position, an air passage through the striker into the space behind the striker piston and an air passage from the said s ace to the cylinder space behind the pellet plston, the fuse being the purpose specified.

adapted on discharge of the shell to cause the set back pin or pins to release both the striker and pellet, whereupon the air pressure dueto the flight of the shell acts on the striker- OWEN DAVID LUCAS. 

